The present invention relates generally to railway pneumatic brake systems and, more specifically, to an interface between a pneumatic train brake control system and a train of electrically controlled pneumatic (ECP) brake equipped cars.
The freight train industry in the U.S. is transitioning from a completely pneumatically-controlled train to a train having ECP brake equipment on their cars. For the foreseeable future, not all locomotives will have the capability of interfacing with an ECP equipped train. They do not have the ability to provide the necessary power or electric control signals to the individual cars nor to control the brake pipe as required by the ECP cars. As presently configured, the train brake pipe is maintained at its charged value and is only used as a pneumatic back-up for failure of the ECP electrical control signals.
To meet this demand, various systems have been suggested. A limp-in control arrangement for ECP systems is described in U.S. Pat. No. 6,286,913. An interface which provides the appropriate level of power to the ECP trainline is described in U.S. Pat. No. 6,217,126. A locomotive to ECP brake conversion system which provides the appropriate power and control signals to the car trainline is described in U.S. Pat. No. 6,189,980.
The present interface system is an improvement over these prior systems and provides additional features. The interface system includes a locomotive electrical trainline terminal and a train electrical trainline terminal. It also includes locomotive and train brake pipe ports and a locomotive pressure supply port. A relay valve is responsive to a pilot signal for connecting the train brake pipe port to the supply port, atmosphere or lap. A controller monitors pressure on the locomotive brake pipe port and controls the pilot signal to the relay valve in response to pressure on the locomotive brake pipe port. The controller also provides ECP commands on the ECP trainline with the train electrical terminal in response to pressure on the locomotive brake pipe port and provides electrical power on the ECP trainline via the train electrical trainline terminal using input power from the locomotive electrical trainline terminal.
A first valve selectively connects the supply port as the pilot signal to the relay valve, and the relay valve compares the supply port""s pressure to the train brake pipe""s pressure. A second valve selectively connects the locomotive brake pipe port to and controls the first valve in response to a signal from the controller. The second valve connects atmosphere to and controls the first valve in response to an emergency signal from the controller or absence of a signal from the controller.
The controller may include a trainline communications controller and a trainline power source connected to the terminals. It may also include a communication node or other suitable interface for connecting the trainline communications controller to the portions of the controller monitoring the pressure and controlling the relay valve. The controller may, alternatively, include a car control device of an ECP brake control valve and a trainline power source connected to the terminals. It would also include a communication node or other suitable interface for connecting the car control device to the portions of the controller monitoring the pressure and controlling the relay valve.
The interface system may also comprise locomotive and train electrical trainline terminals, locomotive and train brake pipe ports and a locomotive pressure supply port. A train brake pipe valve is provided for controlling pressure on the locomotive train brake pipe ports. An emergency valve selectively connects the locomotive brake pipe port to atmosphere in response to an emergency signal. A controller monitors pressure on the locomotive brake pipe port and controls the train brake pipe valve in response to pressure on the locomotive brake pipe port. A controller also monitors pressure on the train brake pipe port and provides the emergency signal to the emergency valve in response to pressure on the train brake pipe port. The controller also provides ECP commands on the train electrical terminal in response to the pressure on the locomotive brake pipe port and provides electrical power on the train electrical trainline terminal from the locomotive electrical trainline terminal.
The controller monitors signals on the train trainline terminal and provides emergency signals to the emergency valve in response to one or more of penalty and emergency signals received on the train electrical trainline terminal. A first valve receives an electrical emergency signal from the controller and provides a pneumatic emergency signal to the emergency valve. A check valve connects the locomotive and train brake pipe ports for an emergency pressure on the train brake pipe port. A vent valve is also provided and is connected to and responsive to an emergency signal on the train""s brake pipe port.
An interface system may also include locomotive and train electrical trainline terminals, locomotive and train brake pipe ports and a locomotive pressure supply port. A controller monitors pressure on the locomotive brake pipe port and controls pressure on the train brake pipe port in response to pressure on the locomotive brake pipe port. A controller also provides ECP commands on the train electrical trainline terminal in response to pressure on the locomotive brake pipe port and provides electrical power on the train electrical trainline terminal from the locomotive electrical trainline terminal. A pair of brake pipe connectors are provided, and a transition valve is provided for reversing the connection of the brake pipe connectors to the locomotive and train brake pipe ports.
The interface system may be mounted on a rail vehicle having two ends. Each end includes a locomotive electrical trainline connector and a train electrical trainline connector connected to the locomotive and train electrical trainline terminals, respectively. It would also include one of the brake pipe connectors connected to the transition valve and a supply connector connected to the supply port.